Reprogramming of Trypanosoma cruzi metabolism triggered by parasite interaction with the host cell extracellular matrix

Trypanosoma cruzi, the etiological agent of Chagas' disease, affects 8 million people predominantly living in socioeconomic underdeveloped areas. T. cruzi trypomastigotes (Ty), the classical infective stage, interact with the extracellular matrix (ECM), an obligatory step before invasion of almost all mammalian cells in different tissues. Here we have characterized the proteome and phosphoproteome of T. cruzi trypomastigotes upon interaction with ECM (MTy) and the data are available via ProteomeXchange with identifier PXD010970. Proteins involved with metabolic processes (such as the glycolytic pathway), kinases, flagellum and microtubule related proteins, transport-associated proteins and RNA/DNA binding elements are highly represented in the pool of proteins modified by phosphorylation. Further, important metabolic switches triggered by this interaction with ECM were indicated by decreases in the phosphorylation of hexokinase, phosphofructokinase, fructose-2,6-bisphosphatase, phosphoglucomutase, phosphoglycerate kinase in MTy. Concomitantly, a decrease in the pyruvate and lactate and an increase of glucose and succinate contents were detected by GC-MS. These observations led us to focus on the changes in the glycolytic pathway upon binding of the parasite to the ECM. Inhibition of hexokinase, pyruvate kinase and lactate dehydrogenase activities in MTy were observed and this correlated with the phosphorylation levels of the respective enzymes. Putative kinases involved in protein phosphorylation altered upon parasite incubation with ECM were suggested by in silico analysis. Taken together, our results show that in addition to cytoskeletal changes and protease activation, a reprogramming of the trypomastigote metabolism is triggered by the interaction of the parasite with the ECM prior to cell invasion and differentiation into amastigotes, the multiplicative intracellular stage of T. cruzi in the vertebrate host. Author summary Adhesion of Trypanosoma cruzi to distinct elements of ECM involving different surface proteins from the infective stage of the parasite has been described. Despite the relevance of ECM for T. cruzi infection, the signaling pathways triggered in trypomastigotes upon interactions with ECM are less well understood. In previous work we demonstrated the dephosphorylation of proteins, such as -tubulin, paraflagellar rod proteins and ERK 1/2 in trypomastigotes incubated with either laminin or fibronectin. Further, we described changes in the S-nitrosylation and nitration pattern of proteins from trypomastigote incubated with ECM. To expand our knowledge on ECM triggered parasite signaling we applied quantitative proteomic and phosphoproteomic studies to trypomastigotes incubated with ECM (MTy) compared to controls (Ty). Our results indicate relevant changes in total protein and phosphoprotein profiles in MTy. The kinases implicated in the modifications were suggested by bioinformatic analyses, as well as the number of modifications and the frequency of amino acids per peptide that have been modified. Proteins involved in metabolic processes, including enzymes from the glycolytic pathway, phosphatases and kinases were the most representative groups among the proteins modified by phosphorylation. Quantification of metabolites in MTy and Ty also indicated that glucose metabolism is impaired in trypomastigotes incubated with ECM. The significant inhibition of hexokinase, pyruvate kinase and lactate dehydrogenase activities in MTy associated with phosphorylation levels, strongly suggests that trypomastigotes reprogram their metabolism in response to interaction with the extracellular matrix, an obligatory step prior to host cell invasion. (AU)